Pittosporum tenuifolium is endemic and widespread throughout New Zealand. Also known as Black Matipo or Kōhūhū. Kōhūhū is found growing wild in coastal and lower mountain forest areas up to an altitude of 900 m. That is nearly every forest type in Canterbury. It grows readily in forested areas that have been disturbed or in reverting farmland, playing an important role in ecological succession. For this reason, it is a key species for forest revegetation. Kōhūhū grows particularly quickly at forest edges located at the bottom of high terraces, also a useful riparian edge plant.
It is highly variable in appearance in nature, with changes to leaf colour and texture as well as growing patterns. As a result, there are many cultivars of the species that can be found in garden centres. It is valued for its coloured foliage. Cultivated variations include purple, “silver” and variegated leaves, none of which are present in a wild population. A truly wild specimen will also not stay naturally compact and can easily reach 10m. However, with annual trimming, even an eco-sourced plant can make an excellent hedge. The compact, small leaves provide privacy year-round and the shrub is low maintenance. Tolerates wind, drought, frost, coastal conditions. Sun or shade.
The leaf coverage is compact in kōhūhū. The leaves themselves are small and the edges are undulated. Leaf shape can range from oval to almost circular, depending on the source. Adult leaves have a smooth, glossy texture.
The flowers’ colour ranges from dark-red to dark-purple turning almost black as the flowers age. Nectar fills the flowers. The flowers exude a honey-scented fragrance in the evenings with the scent being more obvious in slightly damp conditions. This attracts moths and night-flying insects, New Zealand’s indigenous pollinators. Fertilised flowers develop into small fruits that blacken as they ripen.
For more information on plant communities, we recommend DOC’s publication Native Plant Communities of the Canterbury Plains.